Posted on 12/31/2013 7:29:24 AM PST by Abathar
Cloud impact on climate sensitivity unveiled
Global average temperatures will rise at least 4°C by 2100 and potentially more than 8°C by 2200 if carbon dioxide emissions are not reduced according to new research published in Nature. Scientists found global climate is more sensitive to carbon dioxide than most previous estimates.
The research also appears to solve one of the great unknowns of climate sensitivity, the role of cloud formation and whether this will have a positive or negative effect on global warming.
“Our research has shown climate models indicating a low temperature response to a doubling of carbon dioxide from preindustrial times are not reproducing the correct processes that lead to cloud formation," said lead author from the University of New South Wales’ Centre of Excellence for Climate System Science Prof Steven Sherwood.
“When the processes are correct in the climate models the level of climate sensitivity is far higher. Previously, estimates of the sensitivity of global temperature to a doubling of carbon dioxide ranged from 1.5°C to 5°C. This new research takes away the lower end of climate sensitivity estimates, meaning that global average temperatures will increase by 3°C to 5°C with a doubling of carbon dioxide."
The key to this narrower but much higher estimate can be found in the real world observations around the role of water vapour in cloud formation.
Observations show when water vapour is taken up by the atmosphere through evaporation, the updraughts can either rise to 15 km to form clouds that produce heavy rains or rise just a few kilometres before returning to the surface without forming rain clouds.
When updraughts rise only a few kilometres they reduce total cloud cover because they pull more vapour away from the higher cloud forming regions.
However water vapour is not pulled away from cloud forming regions when only deep 15km updraughts are present.
The researchers found climate models that show a low global temperature response to carbon dioxide do not include enough of this lower-level water vapour process. Instead they simulate nearly all updraughts as rising to 15 km and forming clouds.
When only the deeper updraughts are present in climate models, more clouds form and there is an increased reflection of sunlight. Consequently the global climate in these models becomes less sensitive in its response to atmospheric carbon dioxide.
However, real world observations show this behaviour is wrong.
When the processes in climate models are corrected to match the observations in the real world, the models produce cycles that take water vapour to a wider range of heights in the atmosphere, causing fewer clouds to form as the climate warms.
This increases the amount of sunlight and heat entering the atmosphere and, as a result, increases the sensitivity of our climate to carbon dioxide or any other perturbation.
The result is that when water vapour processes are correctly represented, the sensitivity of the climate to a doubling of carbon dioxide - which will occur in the next 50 years – means we can expect a temperature increase of at least 4°C by 2100.
“Climate sceptics like to criticize climate models for getting things wrong, and we are the first to admit they are not perfect, but what we are finding is that the mistakes are being made by those models which predict less warming, not those that predict more,” said Prof. Sherwood.
“Rises in global average temperatures of this magnitude will have profound impacts on the world and the economies of many countries if we don’t urgently start to curb our emissions.
The models forgot to factor in the ice age and weather.
*There is zero global warming.*
And that amount will triple every year!
;-)
Over many decades glider pilots have learned, through multiple observations per flight, that thermals - the rising columns of air mentioned in the article - have a regular spacing. This horizontal spacing is usually 1.5 to 2.5 times the height of the thermal.
Translated into terms of the original article, lower thermals, and the clouds associated with them, are more frequent and closer spaced at low altitudes.
I wonder if their amazing computer models even allowed for multiple thermals over a given area, or just analyzed individual thermals with no relation to adjacent thermals?
I’ll drive a few extra miles today just to see if that helps you out.
TRANSLATION:
“Boop boop dittum dattum wattum, choo!
Mairzy doats and dozy doats and liddle lamzy divey,
Bo Diddley’s a gunslinger!
Goo goo gah jube.
I am the eggman, Whoo!
If you want to keep your insurance,
You can keep your insurance”
I bet none of them, including man-bear-pig, can predict what the weather will be like next Tuesday...
I'm surprised that Al gore doesn't end every sentence with, “That's the ticket!”
I’m glad a ship full of these global warming scientists, these evil chicken littles are stuck in the Ice in Antarctica
My dad headed up PMEL back in the 60's.
I was in PMEL from 73-77 in the USMC and afterwards for civilian companies until 1993............
“Climate research” and politics are one in the same.
You’re a good man. Burn a few tires too, if you got ‘em :)
Shows about a 4% rise in solubility for every degree drop in water temperature. So presuming the oceans have warmed about 1C following the Little Ice Age, how does the corresponding 4% drop in CO2 solubility account for the 40% rise in atmospheric CO2 observed?
I work in the calibration lab at MSFC in Huntsville. You sound like my boss.....(g)
"And he said, "I come from a land down under
Where beer does flow and men chunder blunder
Can't you hear, can't you hear the thunder?
You better run, you better take cover", yeah"
Me thinks they may be hearing the frozen water(ice) thunder. Or someone is firing for range. Uh, trying to break up the frozen water of course.
Testify.
No, they cannot... two days predictions if they are lucky.
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